Bridgestone RFT's on Z4 18"

[Mr Whippy]

Just wondering if anyone knows any seating/bead breaking precautions when working with these tyres...

I want to basically break the bead and re-seat it after an inspection of the seating surface, just not sure if I should be doing it differently to how I would with a normal tyre.

Also the seating pressure to run the tyre up to would be handy if anyone knows.

Thanks for any help/advice

Dave

[DSM2]

Mr Whippy said:

Just wondering if anyone knows any seating/bead breaking precautions when working with these tyres...

I want to basically break the bead and re-seat it after an inspection of the seating surface, just not sure if I should be doing it differently to how I would with a normal tyre.

Also the seating pressure to run the tyre up to would be handy if anyone knows.

Thanks for any help/advice

Dave

What type Tyre changer have you got? The best is one with a rotary bead breaker, so that you can go round and round gently easing the bead off. Corghi Master, A50 or a regualr Corghi with an SP2000 BB.

If a traditional tyre changer with blade BB, work round and round pushing the bead gently off its seat and putting PLENTY of lube in the gap. Don't try to break fully until you have it moving all the way around and there is lub all around too.

when you finally break the bead, it shouldn't take too much pressure. If you go at it as normal and just load the BB up until it goes there is a chance that the blade will, as the bead breaks, shoot under the tyre and whack the side of the well. Many a BMW rim has been cracked like this.

Hope this helps. If you need more PM me and I can send you an NTDA Service Bulletin covering this.

[Mr Whippy]

Yep, it's an old blade BB...

Thats great advice so far thanks... just take it nice and gently then, no rush and lots of lube!

Any spec/best practice on re-inflation/seating? I often push up to 50psi and try let it seat at that, but have seen higher pressures... is there a maximum/minimum I want to be aiming at?


Thanks again

Dave

[DSM2]

Mr Whippy said:

Yep, it's an old blade BB...

Thats great advice so far thanks... just take it nice and gently then, no rush and lots of lube!

Any spec/best practice on re-inflation/seating? I often push up to 50psi and try let it seat at that, but have seen higher pressures... is there a maximum/minimum I want to be aiming at?


Thanks again

Dave

The key when reseating is again lots of lube (Can't stress this enough) If they don't seat at 40psi, push off again and re lube, try again.

Just remembered, the rims will have asymetric humps. when you finally push to break the bead you need to do it at a certain point relative to the valve.

I will check exactly where, first thing in the am, and post.

[DSM2]

With the asymmetric hump BMW rim, you need to break the bead next to where the valve is placed. (After loosening/lubing all round).

The hump, which stops the tyre falling into the well if deflated, is lowest at this point. It is highest opposite the valve.


Just a thought, why are you wanting to check the bead seats? Are you losing pressure? Are you aware that there have been a number of cases of rims cracking, particularly with very low profile tyres? Might be worth checking.

[Mr Whippy]

DSM2 said:

With the asymmetric hump BMW rim, you need to break the bead next to where the valve is placed. (After loosening/lubing all round).

The hump, which stops the tyre falling into the well if deflated, is lowest at this point. It is highest opposite the valve.


Just a thought, why are you wanting to check the bead seats? Are you losing pressure? Are you aware that there have been a number of cases of rims cracking, particularly with very low profile tyres? Might be worth checking.

It takes a few days for the pressure to drop from ~ 33psi > 14psi ish, and then it stops...

I've lubed around the valve and it's blowing bubbles from around the valve (not through it), so it's almost like the valve is badly seated or has been disturbed... just curious if I can get in there and pop a new valve in (I have a feeling it's going to be too tight)

I'm tempted to just get four new tyres anyway (they are all getting on, ok for summer, but not winter really), and get new valves and checked over... going for non-rft's too I think.

In the past I've done my own tyres (up to 17" on a walk around tyre machine), but now it looks like I'll have to go to someone with the expertise/gear to take an rft off and fit a low profile tyre... will be looking at buying a 2nd hand auto machine though I think, as we have and still do, share the cost between the family (about 8 cars, so works out nicely in the longer run)


Thanks

Dave

[DSM2]

Mr Whippy said:

DSM2 said:

With the asymmetric hump BMW rim, you need to break the bead next to where the valve is placed. (After loosening/lubing all round).

The hump, which stops the tyre falling into the well if deflated, is lowest at this point. It is highest opposite the valve.


Just a thought, why are you wanting to check the bead seats? Are you losing pressure? Are you aware that there have been a number of cases of rims cracking, particularly with very low profile tyres? Might be worth checking.

It takes a few days for the pressure to drop from ~ 33psi > 14psi ish, and then it stops...

I've lubed around the valve and it's blowing bubbles from around the valve (not through it), so it's almost like the valve is badly seated or has been disturbed... just curious if I can get in there and pop a new valve in (I have a feeling it's going to be too tight)

I'm tempted to just get four new tyres anyway (they are all getting on, ok for summer, but not winter really), and get new valves and checked over... going for non-rft's too I think.

In the past I've done my own tyres (up to 17" on a walk around tyre machine), but now it looks like I'll have to go to someone with the expertise/gear to take an rft off and fit a low profile tyre... will be looking at buying a 2nd hand auto machine though I think, as we have and still do, share the cost between the family (about 8 cars, so works out nicely in the longer run)


Thanks

Dave

It'll be a bit of a task to get the valve in witout at least lifting the top bead over the rim and fully breaking the rear one! The low profile RFTs are a bit of a sod to fit on a traditional TC too.

What's your budget for a S/H machine? We always have a few around.

[Mr Whippy]

DSM2 said:

Mr Whippy said:

DSM2 said:

With the asymmetric hump BMW rim, you need to break the bead next to where the valve is placed. (After loosening/lubing all round).

The hump, which stops the tyre falling into the well if deflated, is lowest at this point. It is highest opposite the valve.


Just a thought, why are you wanting to check the bead seats? Are you losing pressure? Are you aware that there have been a number of cases of rims cracking, particularly with very low profile tyres? Might be worth checking.

It takes a few days for the pressure to drop from ~ 33psi > 14psi ish, and then it stops...

I've lubed around the valve and it's blowing bubbles from around the valve (not through it), so it's almost like the valve is badly seated or has been disturbed... just curious if I can get in there and pop a new valve in (I have a feeling it's going to be too tight)

I'm tempted to just get four new tyres anyway (they are all getting on, ok for summer, but not winter really), and get new valves and checked over... going for non-rft's too I think.

In the past I've done my own tyres (up to 17" on a walk around tyre machine), but now it looks like I'll have to go to someone with the expertise/gear to take an rft off and fit a low profile tyre... will be looking at buying a 2nd hand auto machine though I think, as we have and still do, share the cost between the family (about 8 cars, so works out nicely in the longer run)


Thanks

Dave

It'll be a bit of a task to get the valve in witout at least lifting the top bead over the rim and fully breaking the rear one! The low profile RFTs are a bit of a sod to fit on a traditional TC too.

What's your budget for a S/H machine? We always have a few around.

Not really sure as we have just started looking, as we are thinking of building a new private family garage too... I wanted a balancing machine as well.

I'm just watching prices on ebay and keeping a bit of a record of what kind of prices are right for certain kit. I don't think we'll want to spend much over £600 ish though for the machine, but again, it just depends how much things are in summer.

Dave

Edited by Mr Whippy on Friday 30th January 12:26

[StuB]

Dave, I'd take it into a pro if I were you and watch in person as I've ended up with a cracked rim as a result of a clumsy tyre fitter, which I'm told isn't that unusual due to the force that needs to be applied to remove the tyre!

HTH

[DSM2]

StuB said:

Dave, I'd take it into a pro if I were you and watch in person as I've ended up with a cracked rim as a result of a clumsy tyre fitter, which I'm told isn't that unusual due to the force that needs to be applied to remove the tyre!

HTH

You're right StuB, that has been a not uncommon event, and happens as I've explained in my earlier post.

Dave, let me know if and when, I am sure we could help you. We are the UK agents for Corghi, probably the best tyre changers in the world(!) and have all sorts and price levels of new and used kit. Balancers too.

[Mr Whippy]

DSM2 said:

StuB said:

Dave, I'd take it into a pro if I were you and watch in person as I've ended up with a cracked rim as a result of a clumsy tyre fitter, which I'm told isn't that unusual due to the force that needs to be applied to remove the tyre!

HTH

You're right StuB, that has been a not uncommon event, and happens as I've explained in my earlier post.

Dave, let me know if and when, I am sure we could help you. We are the UK agents for Corghi, probably the best tyre changers in the world(!) and have all sorts and price levels of new and used kit. Balancers too.

Ah cool!

Thanks Stu, I think I'll be finding a good place. Tockwith Tyres seem ok by their feedback on the online tyre seller sites, so might give them a try...

Just deciding which tyres to get now. More Bridgestone RFT's, or punt for some non-RFT's...

Dave

[StuB]

I've been running None RFT's on the back of my E60 for at least 6 months and so far so good - no issues with Tyre Pressure Warnings, autobox getting knickers in a twist or anything. I have a large can of tyreweld in the boot for emergencies as the space saver for the 5er is also ridiculously priced (yes it's a priced option )

I just wish I had been more inclined to ditch the fronts, but they were nearly new.

The Z4 specific sites might have plenty of recommendations and I know of one guy who's propper toy is a Radical SR3, so I think he knows his stuff! He's on www.zed.cars.eu if you're interested.

It seems most RFT's feel like normal tyres running 60psi! From memory, the Goodyears I had on last (still on the front) have been the pick to date IMO.

[Mr Whippy]

StuB said:

I've been running None RFT's on the back of my E60 for at least 6 months and so far so good - no issues with Tyre Pressure Warnings, autobox getting knickers in a twist or anything. I have a large can of tyreweld in the boot for emergencies as the space saver for the 5er is also ridiculously priced (yes it's a priced option )

I just wish I had been more inclined to ditch the fronts, but they were nearly new.

The Z4 specific sites might have plenty of recommendations and I know of one guy who's propper toy is a Radical SR3, so I think he knows his stuff! He's on www.zed.cars.eu if you're interested.

It seems most RFT's feel like normal tyres running 60psi! From memory, the Goodyears I had on last (still on the front) have been the pick to date IMO.

I'm looking mainly at Flaken FK452's which a few Z4 owners seem to rate, and also Goodyear Asymmetrics, which cost a bit more but look like one of the top tyres out there full stop.

Then there are the OEM RFT's, but for £20 more per corner I'd prefer to get the Michelin ZP PS2's which are apparently amazing, while still retaining run flat capability. Just at £200 fronts, £230 rears, vs £400 for all four for FK452's, I don't think I'll bother

Need to decide soon though... will post on the Yorkshire thread about a *good* local tyre fitter...

Dave